arch/x86/Kconfig

   1 # x86 configuration
   2 mainmenu "Linux Kernel Configuration for x86"
   3
   4 # Select 32 or 64 bit
   5 config 64BIT
   6         bool "64-bit kernel" if ARCH = "x86"
   7         default ARCH = "x86_64"
   8         ---help---
   9           Say yes to build a 64-bit kernel - formerly known as x86_64
  10           Say no to build a 32-bit kernel - formerly known as i386
  11
  12 config X86_32
  13         def_bool !64BIT
  14
  15 config X86_64
  16         def_bool 64BIT
  17
  18 ### Arch settings
  19 config X86
  20         def_bool y
  21         select HAVE_AOUT if X86_32
  22         select HAVE_READQ
  23         select HAVE_WRITEQ
  24         select HAVE_UNSTABLE_SCHED_CLOCK
  25         select HAVE_IDE
  26         select HAVE_OPROFILE
  27         select HAVE_PERF_EVENTS if (!M386 && !M486)
  28         select HAVE_IOREMAP_PROT
  29         select HAVE_KPROBES
  30         select ARCH_WANT_OPTIONAL_GPIOLIB
  31         select ARCH_WANT_FRAME_POINTERS
  32         select HAVE_DMA_ATTRS
  33         select HAVE_KRETPROBES
  34         select HAVE_OPTPROBES
  35         select HAVE_FTRACE_MCOUNT_RECORD
  36         select HAVE_DYNAMIC_FTRACE
  37         select HAVE_FUNCTION_TRACER
  38         select HAVE_FUNCTION_GRAPH_TRACER
  39         select HAVE_FUNCTION_GRAPH_FP_TEST
  40         select HAVE_FUNCTION_TRACE_MCOUNT_TEST
  41         select HAVE_FTRACE_NMI_ENTER if DYNAMIC_FTRACE
  42         select HAVE_SYSCALL_TRACEPOINTS
  43         select HAVE_KVM
  44         select HAVE_ARCH_KGDB
  45         select HAVE_ARCH_TRACEHOOK
  46         select HAVE_GENERIC_DMA_COHERENT if X86_32
  47         select HAVE_EFFICIENT_UNALIGNED_ACCESS
  48         select USER_STACKTRACE_SUPPORT
  49         select HAVE_REGS_AND_STACK_ACCESS_API
  50         select HAVE_DMA_API_DEBUG
  51         select HAVE_KERNEL_GZIP
  52         select HAVE_KERNEL_BZIP2
  53         select HAVE_KERNEL_LZMA
  54         select HAVE_KERNEL_LZO
  55         select HAVE_HW_BREAKPOINT
  56         select HAVE_MIXED_BREAKPOINTS_REGS
  57         select PERF_EVENTS
  58         select HAVE_PERF_EVENTS_NMI
  59         select ANON_INODES
  60         select HAVE_ARCH_KMEMCHECK
  61         select HAVE_USER_RETURN_NOTIFIER
  62
  63 config INSTRUCTION_DECODER
  64         def_bool (KPROBES || PERF_EVENTS)
  65
  66 config OUTPUT_FORMAT
  67         string
  68         default "elf32-i386" if X86_32
  69         default "elf64-x86-64" if X86_64
  70
  71 config ARCH_DEFCONFIG
  72         string
  73         default "arch/x86/configs/i386_defconfig" if X86_32
  74         default "arch/x86/configs/x86_64_defconfig" if X86_64
  75
  76 config GENERIC_CMOS_UPDATE
  77         def_bool y
  78
  79 config CLOCKSOURCE_WATCHDOG
  80         def_bool y
  81
  82 config GENERIC_CLOCKEVENTS
  83         def_bool y
  84
  85 config GENERIC_CLOCKEVENTS_BROADCAST
  86         def_bool y
  87         depends on X86_64 || (X86_32 && X86_LOCAL_APIC)
  88
  89 config LOCKDEP_SUPPORT
  90         def_bool y
  91
  92 config STACKTRACE_SUPPORT
  93         def_bool y
  94
  95 config HAVE_LATENCYTOP_SUPPORT
  96         def_bool y
  97
  98 config MMU
  99         def_bool y
 100
 101 config ZONE_DMA
 102         def_bool y
 103
 104 config SBUS
 105         bool
 106
 107 config NEED_DMA_MAP_STATE
 108        def_bool (X86_64 || DMAR || DMA_API_DEBUG)
 109
 110 config NEED_SG_DMA_LENGTH
 111         def_bool y
 112
 113 config GENERIC_ISA_DMA
 114         def_bool y
 115
 116 config GENERIC_IOMAP
 117         def_bool y
 118
 119 config GENERIC_BUG
 120         def_bool y
 121         depends on BUG
 122         select GENERIC_BUG_RELATIVE_POINTERS if X86_64
 123
 124 config GENERIC_BUG_RELATIVE_POINTERS
 125         bool
 126
 127 config GENERIC_HWEIGHT
 128         def_bool y
 129
 130 config GENERIC_GPIO
 131         bool
 132
 133 config ARCH_MAY_HAVE_PC_FDC
 134         def_bool y
 135
 136 config RWSEM_GENERIC_SPINLOCK
 137         def_bool !X86_XADD
 138
 139 config RWSEM_XCHGADD_ALGORITHM
 140         def_bool X86_XADD
 141
 142 config ARCH_HAS_CPU_IDLE_WAIT
 143         def_bool y
 144
 145 config GENERIC_CALIBRATE_DELAY
 146         def_bool y
 147
 148 config GENERIC_TIME_VSYSCALL
 149         bool
 150         default X86_64
 151
 152 config ARCH_HAS_CPU_RELAX
 153         def_bool y
 154
 155 config ARCH_HAS_DEFAULT_IDLE
 156         def_bool y
 157
 158 config ARCH_HAS_CACHE_LINE_SIZE
 159         def_bool y
 160
 161 config HAVE_SETUP_PER_CPU_AREA
 162         def_bool y
 163
 164 config NEED_PER_CPU_EMBED_FIRST_CHUNK
 165         def_bool y
 166
 167 config NEED_PER_CPU_PAGE_FIRST_CHUNK
 168         def_bool y
 169
 170 config HAVE_CPUMASK_OF_CPU_MAP
 171         def_bool X86_64_SMP
 172
 173 config ARCH_HIBERNATION_POSSIBLE
 174         def_bool y
 175
 176 config ARCH_SUSPEND_POSSIBLE
 177         def_bool y
 178
 179 config ZONE_DMA32
 180         bool
 181         default X86_64
 182
 183 config ARCH_POPULATES_NODE_MAP
 184         def_bool y
 185
 186 config AUDIT_ARCH
 187         bool
 188         default X86_64
 189
 190 config ARCH_SUPPORTS_OPTIMIZED_INLINING
 191         def_bool y
 192
 193 config ARCH_SUPPORTS_DEBUG_PAGEALLOC
 194         def_bool y
 195
 196 config HAVE_EARLY_RES
 197         def_bool y
 198
 199 config HAVE_INTEL_TXT
 200         def_bool y
 201         depends on EXPERIMENTAL && DMAR && ACPI
 202
 203 # Use the generic interrupt handling code in kernel/irq/:
 204 config GENERIC_HARDIRQS
 205         def_bool y
 206
 207 config GENERIC_HARDIRQS_NO__DO_IRQ
 208        def_bool y
 209
 210 config GENERIC_IRQ_PROBE
 211         def_bool y
 212
 213 config GENERIC_PENDING_IRQ
 214         def_bool y
 215         depends on GENERIC_HARDIRQS && SMP
 216
 217 config USE_GENERIC_SMP_HELPERS
 218         def_bool y
 219         depends on SMP
 220
 221 config X86_32_SMP
 222         def_bool y
 223         depends on X86_32 && SMP
 224
 225 config X86_64_SMP
 226         def_bool y
 227         depends on X86_64 && SMP
 228
 229 config X86_HT
 230         def_bool y
 231         depends on SMP
 232
 233 config X86_TRAMPOLINE
 234         def_bool y
 235         depends on SMP || (64BIT && ACPI_SLEEP)
 236
 237 config X86_32_LAZY_GS
 238         def_bool y
 239         depends on X86_32 && !CC_STACKPROTECTOR
 240
 241 config ARCH_HWEIGHT_CFLAGS
 242         string
 243         default "-fcall-saved-ecx -fcall-saved-edx" if X86_32
 244         default "-fcall-saved-rdi -fcall-saved-rsi -fcall-saved-rdx -fcall-saved-rcx -fcall-saved-r8 -fcall-saved-r9 -fcall-saved-r10 -fcall-saved-r11" if X86_64
 245
 246 config KTIME_SCALAR
 247         def_bool X86_32
 248
 249 config ARCH_CPU_PROBE_RELEASE
 250         def_bool y
 251         depends on HOTPLUG_CPU
 252
 253 source "init/Kconfig"
 254 source "kernel/Kconfig.freezer"
 255
 256 menu "Processor type and features"
 257
 258 source "kernel/time/Kconfig"
 259
 260 config SMP
 261         bool "Symmetric multi-processing support"
 262         ---help---
 263           This enables support for systems with more than one CPU. If you have
 264           a system with only one CPU, like most personal computers, say N. If
 265           you have a system with more than one CPU, say Y.
 266
 267           If you say N here, the kernel will run on single and multiprocessor
 268           machines, but will use only one CPU of a multiprocessor machine. If
 269           you say Y here, the kernel will run on many, but not all,
 270           singleprocessor machines. On a singleprocessor machine, the kernel
 271           will run faster if you say N here.
 272
 273           Note that if you say Y here and choose architecture "586" or
 274           "Pentium" under "Processor family", the kernel will not work on 486
 275           architectures. Similarly, multiprocessor kernels for the "PPro"
 276           architecture may not work on all Pentium based boards.
 277
 278           People using multiprocessor machines who say Y here should also say
 279           Y to "Enhanced Real Time Clock Support", below. The "Advanced Power
 280           Management" code will be disabled if you say Y here.
 281
 282           See also <file:Documentation/i386/IO-APIC.txt>,
 283           <file:Documentation/nmi_watchdog.txt> and the SMP-HOWTO available at
 284           <http://www.tldp.org/docs.html#howto>.
 285
 286           If you don't know what to do here, say N.
 287
 288 config X86_X2APIC
 289         bool "Support x2apic"
 290         depends on X86_LOCAL_APIC && X86_64 && INTR_REMAP
 291         ---help---
 292           This enables x2apic support on CPUs that have this feature.
 293
 294           This allows 32-bit apic IDs (so it can support very large systems),
 295           and accesses the local apic via MSRs not via mmio.
 296
 297           If you don't know what to do here, say N.
 298
 299 config SPARSE_IRQ
 300         bool "Support sparse irq numbering"
 301         depends on PCI_MSI || HT_IRQ
 302         ---help---
 303           This enables support for sparse irqs. This is useful for distro
 304           kernels that want to define a high CONFIG_NR_CPUS value but still
 305           want to have low kernel memory footprint on smaller machines.
 306
 307           ( Sparse IRQs can also be beneficial on NUMA boxes, as they spread
 308             out the irq_desc[] array in a more NUMA-friendly way. )
 309
 310           If you don't know what to do here, say N.
 311
 312 config NUMA_IRQ_DESC
 313         def_bool y
 314         depends on SPARSE_IRQ && NUMA
 315
 316 config X86_MPPARSE
 317         bool "Enable MPS table" if ACPI
 318         default y
 319         depends on X86_LOCAL_APIC
 320         ---help---
 321           For old smp systems that do not have proper acpi support. Newer systems
 322           (esp with 64bit cpus) with acpi support, MADT and DSDT will override it
 323
 324 config X86_BIGSMP
 325         bool "Support for big SMP systems with more than 8 CPUs"
 326         depends on X86_32 && SMP
 327         ---help---
 328           This option is needed for the systems that have more than 8 CPUs
 329
 330 if X86_32
 331 config X86_EXTENDED_PLATFORM
 332         bool "Support for extended (non-PC) x86 platforms"
 333         default y
 334         ---help---
 335           If you disable this option then the kernel will only support
 336           standard PC platforms. (which covers the vast majority of
 337           systems out there.)
 338
 339           If you enable this option then you'll be able to select support
 340           for the following (non-PC) 32 bit x86 platforms:
 341                 AMD Elan
 342                 NUMAQ (IBM/Sequent)
 343                 RDC R-321x SoC
 344                 SGI 320/540 (Visual Workstation)
 345                 Summit/EXA (IBM x440)
 346                 Unisys ES7000 IA32 series
 347                 Moorestown MID devices
 348
 349           If you have one of these systems, or if you want to build a
 350           generic distribution kernel, say Y here - otherwise say N.
 351 endif
 352
 353 if X86_64
 354 config X86_EXTENDED_PLATFORM
 355         bool "Support for extended (non-PC) x86 platforms"
 356         default y
 357         ---help---
 358           If you disable this option then the kernel will only support
 359           standard PC platforms. (which covers the vast majority of
 360           systems out there.)
 361
 362           If you enable this option then you'll be able to select support
 363           for the following (non-PC) 64 bit x86 platforms:
 364                 ScaleMP vSMP
 365                 SGI Ultraviolet
 366
 367           If you have one of these systems, or if you want to build a
 368           generic distribution kernel, say Y here - otherwise say N.
 369 endif
 370 # This is an alphabetically sorted list of 64 bit extended platforms
 371 # Please maintain the alphabetic order if and when there are additions
 372
 373 config X86_VSMP
 374         bool "ScaleMP vSMP"
 375         select PARAVIRT
 376         depends on X86_64 && PCI
 377         depends on X86_EXTENDED_PLATFORM
 378         ---help---
 379           Support for ScaleMP vSMP systems.  Say 'Y' here if this kernel is
 380           supposed to run on these EM64T-based machines.  Only choose this option
 381           if you have one of these machines.
 382
 383 config X86_UV
 384         bool "SGI Ultraviolet"
 385         depends on X86_64
 386         depends on X86_EXTENDED_PLATFORM
 387         depends on NUMA
 388         depends on X86_X2APIC
 389         ---help---
 390           This option is needed in order to support SGI Ultraviolet systems.
 391           If you don't have one of these, you should say N here.
 392
 393 # Following is an alphabetically sorted list of 32 bit extended platforms
 394 # Please maintain the alphabetic order if and when there are additions
 395
 396 config X86_ELAN
 397         bool "AMD Elan"
 398         depends on X86_32
 399         depends on X86_EXTENDED_PLATFORM
 400         ---help---
 401           Select this for an AMD Elan processor.
 402
 403           Do not use this option for K6/Athlon/Opteron processors!
 404
 405           If unsure, choose "PC-compatible" instead.
 406
 407 config X86_MRST
 408        bool "Moorestown MID platform"
 409         depends on PCI
 410         depends on PCI_GOANY
 411         depends on X86_32
 412         depends on X86_EXTENDED_PLATFORM
 413         depends on X86_IO_APIC
 414         select APB_TIMER
 415         ---help---
 416           Moorestown is Intel's Low Power Intel Architecture (LPIA) based Moblin
 417           Internet Device(MID) platform. Moorestown consists of two chips:
 418           Lincroft (CPU core, graphics, and memory controller) and Langwell IOH.
 419           Unlike standard x86 PCs, Moorestown does not have many legacy devices
 420           nor standard legacy replacement devices/features. e.g. Moorestown does
 421           not contain i8259, i8254, HPET, legacy BIOS, most of the io ports.
 422
 423 config X86_RDC321X
 424         bool "RDC R-321x SoC"
 425         depends on X86_32
 426         depends on X86_EXTENDED_PLATFORM
 427         select M486
 428         select X86_REBOOTFIXUPS
 429         ---help---
 430           This option is needed for RDC R-321x system-on-chip, also known
 431           as R-8610-(G).
 432           If you don't have one of these chips, you should say N here.
 433
 434 config X86_32_NON_STANDARD
 435         bool "Support non-standard 32-bit SMP architectures"
 436         depends on X86_32 && SMP
 437         depends on X86_EXTENDED_PLATFORM
 438         ---help---
 439           This option compiles in the NUMAQ, Summit, bigsmp, ES7000, default
 440           subarchitectures.  It is intended for a generic binary kernel.
 441           if you select them all, kernel will probe it one by one. and will
 442           fallback to default.
 443
 444 # Alphabetically sorted list of Non standard 32 bit platforms
 445
 446 config X86_NUMAQ
 447         bool "NUMAQ (IBM/Sequent)"
 448         depends on X86_32_NON_STANDARD
 449         depends on PCI
 450         select NUMA
 451         select X86_MPPARSE
 452         ---help---
 453           This option is used for getting Linux to run on a NUMAQ (IBM/Sequent)
 454           NUMA multiquad box. This changes the way that processors are
 455           bootstrapped, and uses Clustered Logical APIC addressing mode instead
 456           of Flat Logical.  You will need a new lynxer.elf file to flash your
 457           firmware with - send email to <Martin.Bligh@us.ibm.com>.
 458
 459 config X86_SUPPORTS_MEMORY_FAILURE
 460         def_bool y
 461         # MCE code calls memory_failure():
 462         depends on X86_MCE
 463         # On 32-bit this adds too big of NODES_SHIFT and we run out of page flags:
 464         depends on !X86_NUMAQ
 465         # On 32-bit SPARSEMEM adds too big of SECTIONS_WIDTH:
 466         depends on X86_64 || !SPARSEMEM
 467         select ARCH_SUPPORTS_MEMORY_FAILURE
 468
 469 config X86_VISWS
 470         bool "SGI 320/540 (Visual Workstation)"
 471         depends on X86_32 && PCI && X86_MPPARSE && PCI_GODIRECT
 472         depends on X86_32_NON_STANDARD
 473         ---help---
 474           The SGI Visual Workstation series is an IA32-based workstation
 475           based on SGI systems chips with some legacy PC hardware attached.
 476
 477           Say Y here to create a kernel to run on the SGI 320 or 540.
 478
 479           A kernel compiled for the Visual Workstation will run on general
 480           PCs as well. See <file:Documentation/sgi-visws.txt> for details.
 481
 482 config X86_SUMMIT
 483         bool "Summit/EXA (IBM x440)"
 484         depends on X86_32_NON_STANDARD
 485         ---help---
 486           This option is needed for IBM systems that use the Summit/EXA chipset.
 487           In particular, it is needed for the x440.
 488
 489 config X86_ES7000
 490         bool "Unisys ES7000 IA32 series"
 491         depends on X86_32_NON_STANDARD && X86_BIGSMP
 492         ---help---
 493           Support for Unisys ES7000 systems.  Say 'Y' here if this kernel is
 494           supposed to run on an IA32-based Unisys ES7000 system.
 495
 496 config SCHED_OMIT_FRAME_POINTER
 497         def_bool y
 498         prompt "Single-depth WCHAN output"
 499         depends on X86
 500         ---help---
 501           Calculate simpler /proc/<PID>/wchan values. If this option
 502           is disabled then wchan values will recurse back to the
 503           caller function. This provides more accurate wchan values,
 504           at the expense of slightly more scheduling overhead.
 505
 506           If in doubt, say "Y".
 507
 508 menuconfig PARAVIRT_GUEST
 509         bool "Paravirtualized guest support"
 510         ---help---
 511           Say Y here to get to see options related to running Linux under
 512           various hypervisors.  This option alone does not add any kernel code.
 513
 514           If you say N, all options in this submenu will be skipped and disabled.
 515
 516 if PARAVIRT_GUEST
 517
 518 source "arch/x86/xen/Kconfig"
 519
 520 config KVM_CLOCK
 521         bool "KVM paravirtualized clock"
 522         select PARAVIRT
 523         select PARAVIRT_CLOCK
 524         ---help---
 525           Turning on this option will allow you to run a paravirtualized clock
 526           when running over the KVM hypervisor. Instead of relying on a PIT
 527           (or probably other) emulation by the underlying device model, the host
 528           provides the guest with timing infrastructure such as time of day, and
 529           system time
 530
 531 config KVM_GUEST
 532         bool "KVM Guest support"
 533         select PARAVIRT
 534         ---help---
 535           This option enables various optimizations for running under the KVM
 536           hypervisor.
 537
 538 source "arch/x86/lguest/Kconfig"
 539
 540 config PARAVIRT
 541         bool "Enable paravirtualization code"
 542         ---help---
 543           This changes the kernel so it can modify itself when it is run
 544           under a hypervisor, potentially improving performance significantly
 545           over full virtualization.  However, when run without a hypervisor
 546           the kernel is theoretically slower and slightly larger.
 547
 548 config PARAVIRT_SPINLOCKS
 549         bool "Paravirtualization layer for spinlocks"
 550         depends on PARAVIRT && SMP && EXPERIMENTAL
 551         ---help---
 552           Paravirtualized spinlocks allow a pvops backend to replace the
 553           spinlock implementation with something virtualization-friendly
 554           (for example, block the virtual CPU rather than spinning).
 555
 556           Unfortunately the downside is an up to 5% performance hit on
 557           native kernels, with various workloads.
 558
 559           If you are unsure how to answer this question, answer N.
 560
 561 config PARAVIRT_CLOCK
 562         bool
 563
 564 endif
 565
 566 config PARAVIRT_DEBUG
 567         bool "paravirt-ops debugging"
 568         depends on PARAVIRT && DEBUG_KERNEL
 569         ---help---
 570           Enable to debug paravirt_ops internals.  Specifically, BUG if
 571           a paravirt_op is missing when it is called.
 572
 573 config NO_BOOTMEM
 574         default y
 575         bool "Disable Bootmem code"
 576         ---help---
 577           Use early_res directly instead of bootmem before slab is ready.
 578                 - allocator (buddy) [generic]
 579                 - early allocator (bootmem) [generic]
 580                 - very early allocator (reserve_early*()) [x86]
 581                 - very very early allocator (early brk model) [x86]
 582           So reduce one layer between early allocator to final allocator
 583
 584
 585 config MEMTEST
 586         bool "Memtest"
 587         ---help---
 588           This option adds a kernel parameter 'memtest', which allows memtest
 589           to be set.
 590                 memtest=0, mean disabled; -- default
 591                 memtest=1, mean do 1 test pattern;
 592                 ...
 593                 memtest=4, mean do 4 test patterns.
 594           If you are unsure how to answer this question, answer N.
 595
 596 config X86_SUMMIT_NUMA
 597         def_bool y
 598         depends on X86_32 && NUMA && X86_32_NON_STANDARD
 599
 600 config X86_CYCLONE_TIMER
 601         def_bool y
 602         depends on X86_32_NON_STANDARD
 603
 604 source "arch/x86/Kconfig.cpu"
 605
 606 config HPET_TIMER
 607         def_bool X86_64
 608         prompt "HPET Timer Support" if X86_32
 609         ---help---
 610           Use the IA-PC HPET (High Precision Event Timer) to manage
 611           time in preference to the PIT and RTC, if a HPET is
 612           present.
 613           HPET is the next generation timer replacing legacy 8254s.
 614           The HPET provides a stable time base on SMP
 615           systems, unlike the TSC, but it is more expensive to access,
 616           as it is off-chip.  You can find the HPET spec at
 617           <http://www.intel.com/hardwaredesign/hpetspec_1.pdf>.
 618
 619           You can safely choose Y here.  However, HPET will only be
 620           activated if the platform and the BIOS support this feature.
 621           Otherwise the 8254 will be used for timing services.
 622
 623           Choose N to continue using the legacy 8254 timer.
 624
 625 config HPET_EMULATE_RTC
 626         def_bool y
 627         depends on HPET_TIMER && (RTC=y || RTC=m || RTC_DRV_CMOS=m || RTC_DRV_CMOS=y)
 628
 629 config APB_TIMER
 630        def_bool y if MRST
 631        prompt "Langwell APB Timer Support" if X86_MRST
 632        help
 633          APB timer is the replacement for 8254, HPET on X86 MID platforms.
 634          The APBT provides a stable time base on SMP
 635          systems, unlike the TSC, but it is more expensive to access,
 636          as it is off-chip. APB timers are always running regardless of CPU
 637          C states, they are used as per CPU clockevent device when possible.
 638
 639 # Mark as embedded because too many people got it wrong.
 640 # The code disables itself when not needed.
 641 config DMI
 642         default y
 643         bool "Enable DMI scanning" if EMBEDDED
 644         ---help---
 645           Enabled scanning of DMI to identify machine quirks. Say Y
 646           here unless you have verified that your setup is not
 647           affected by entries in the DMI blacklist. Required by PNP
 648           BIOS code.
 649
 650 config GART_IOMMU
 651         bool "GART IOMMU support" if EMBEDDED
 652         default y
 653         select SWIOTLB
 654         depends on X86_64 && PCI && K8_NB
 655         ---help---
 656           Support for full DMA access of devices with 32bit memory access only
 657           on systems with more than 3GB. This is usually needed for USB,
 658           sound, many IDE/SATA chipsets and some other devices.
 659           Provides a driver for the AMD Athlon64/Opteron/Turion/Sempron GART
 660           based hardware IOMMU and a software bounce buffer based IOMMU used
 661           on Intel systems and as fallback.
 662           The code is only active when needed (enough memory and limited
 663           device) unless CONFIG_IOMMU_DEBUG or iommu=force is specified
 664           too.
 665
 666 config CALGARY_IOMMU
 667         bool "IBM Calgary IOMMU support"
 668         select SWIOTLB
 669         depends on X86_64 && PCI && EXPERIMENTAL
 670         ---help---
 671           Support for hardware IOMMUs in IBM's xSeries x366 and x460
 672           systems. Needed to run systems with more than 3GB of memory
 673           properly with 32-bit PCI devices that do not support DAC
 674           (Double Address Cycle). Calgary also supports bus level
 675           isolation, where all DMAs pass through the IOMMU.  This
 676           prevents them from going anywhere except their intended
 677           destination. This catches hard-to-find kernel bugs and
 678           mis-behaving drivers and devices that do not use the DMA-API
 679           properly to set up their DMA buffers.  The IOMMU can be
 680           turned off at boot time with the iommu=off parameter.
 681           Normally the kernel will make the right choice by itself.
 682           If unsure, say Y.
 683
 684 config CALGARY_IOMMU_ENABLED_BY_DEFAULT
 685         def_bool y
 686         prompt "Should Calgary be enabled by default?"
 687         depends on CALGARY_IOMMU
 688         ---help---
 689           Should Calgary be enabled by default? if you choose 'y', Calgary
 690           will be used (if it exists). If you choose 'n', Calgary will not be
 691           used even if it exists. If you choose 'n' and would like to use
 692           Calgary anyway, pass 'iommu=calgary' on the kernel command line.
 693           If unsure, say Y.
 694
 695 config AMD_IOMMU
 696         bool "AMD IOMMU support"
 697         select SWIOTLB
 698         select PCI_MSI
 699         depends on X86_64 && PCI && ACPI
 700         ---help---
 701           With this option you can enable support for AMD IOMMU hardware in
 702           your system. An IOMMU is a hardware component which provides
 703           remapping of DMA memory accesses from devices. With an AMD IOMMU you
 704           can isolate the the DMA memory of different devices and protect the
 705           system from misbehaving device drivers or hardware.
 706
 707           You can find out if your system has an AMD IOMMU if you look into
 708           your BIOS for an option to enable it or if you have an IVRS ACPI
 709           table.
 710
 711 config AMD_IOMMU_STATS
 712         bool "Export AMD IOMMU statistics to debugfs"
 713         depends on AMD_IOMMU
 714         select DEBUG_FS
 715         ---help---
 716           This option enables code in the AMD IOMMU driver to collect various
 717           statistics about whats happening in the driver and exports that
 718           information to userspace via debugfs.
 719           If unsure, say N.
 720
 721 # need this always selected by IOMMU for the VIA workaround
 722 config SWIOTLB
 723         def_bool y if X86_64
 724         ---help---
 725           Support for software bounce buffers used on x86-64 systems
 726           which don't have a hardware IOMMU (e.g. the current generation
 727           of Intel's x86-64 CPUs). Using this PCI devices which can only
 728           access 32-bits of memory can be used on systems with more than
 729           3 GB of memory. If unsure, say Y.
 730
 731 config IOMMU_HELPER
 732         def_bool (CALGARY_IOMMU || GART_IOMMU || SWIOTLB || AMD_IOMMU)
 733
 734 config IOMMU_API
 735         def_bool (AMD_IOMMU || DMAR)
 736
 737 config MAXSMP
 738         bool "Enable Maximum number of SMP Processors and NUMA Nodes"
 739         depends on X86_64 && SMP && DEBUG_KERNEL && EXPERIMENTAL
 740         select CPUMASK_OFFSTACK
 741         ---help---
 742           Enable maximum number of CPUS and NUMA Nodes for this architecture.
 743           If unsure, say N.
 744
 745 config NR_CPUS
 746         int "Maximum number of CPUs" if SMP && !MAXSMP
 747         range 2 8 if SMP && X86_32 && !X86_BIGSMP
 748         range 2 512 if SMP && !MAXSMP
 749         default "1" if !SMP
 750         default "4096" if MAXSMP
 751         default "32" if SMP && (X86_NUMAQ || X86_SUMMIT || X86_BIGSMP || X86_ES7000)
 752         default "8" if SMP
 753         ---help---
 754           This allows you to specify the maximum number of CPUs which this
 755           kernel will support.  The maximum supported value is 512 and the
 756           minimum value which makes sense is 2.
 757
 758           This is purely to save memory - each supported CPU adds
 759           approximately eight kilobytes to the kernel image.
 760
 761 config SCHED_SMT
 762         bool "SMT (Hyperthreading) scheduler support"
 763         depends on X86_HT
 764         ---help---
 765           SMT scheduler support improves the CPU scheduler's decision making
 766           when dealing with Intel Pentium 4 chips with HyperThreading at a
 767           cost of slightly increased overhead in some places. If unsure say
 768           N here.
 769
 770 config SCHED_MC
 771         def_bool y
 772         prompt "Multi-core scheduler support"
 773         depends on X86_HT
 774         ---help---
 775           Multi-core scheduler support improves the CPU scheduler's decision
 776           making when dealing with multi-core CPU chips at a cost of slightly
 777           increased overhead in some places. If unsure say N here.
 778
 779 source "kernel/Kconfig.preempt"
 780
 781 config X86_UP_APIC
 782         bool "Local APIC support on uniprocessors"
 783         depends on X86_32 && !SMP && !X86_32_NON_STANDARD
 784         ---help---
 785           A local APIC (Advanced Programmable Interrupt Controller) is an
 786           integrated interrupt controller in the CPU. If you have a single-CPU
 787           system which has a processor with a local APIC, you can say Y here to
 788           enable and use it. If you say Y here even though your machine doesn't
 789           have a local APIC, then the kernel will still run with no slowdown at
 790           all. The local APIC supports CPU-generated self-interrupts (timer,
 791           performance counters), and the NMI watchdog which detects hard
 792           lockups.
 793
 794 config X86_UP_IOAPIC
 795         bool "IO-APIC support on uniprocessors"
 796         depends on X86_UP_APIC
 797         ---help---
 798           An IO-APIC (I/O Advanced Programmable Interrupt Controller) is an
 799           SMP-capable replacement for PC-style interrupt controllers. Most
 800           SMP systems and many recent uniprocessor systems have one.
 801
 802           If you have a single-CPU system with an IO-APIC, you can say Y here
 803           to use it. If you say Y here even though your machine doesn't have
 804           an IO-APIC, then the kernel will still run with no slowdown at all.
 805
 806 config X86_LOCAL_APIC
 807         def_bool y
 808         depends on X86_64 || SMP || X86_32_NON_STANDARD || X86_UP_APIC
 809
 810 config X86_IO_APIC
 811         def_bool y
 812         depends on X86_64 || SMP || X86_32_NON_STANDARD || X86_UP_APIC
 813
 814 config X86_VISWS_APIC
 815         def_bool y
 816         depends on X86_32 && X86_VISWS
 817
 818 config X86_REROUTE_FOR_BROKEN_BOOT_IRQS
 819         bool "Reroute for broken boot IRQs"
 820         depends on X86_IO_APIC
 821         ---help---
 822           This option enables a workaround that fixes a source of
 823           spurious interrupts. This is recommended when threaded
 824           interrupt handling is used on systems where the generation of
 825           superfluous "boot interrupts" cannot be disabled.
 826
 827           Some chipsets generate a legacy INTx "boot IRQ" when the IRQ
 828           entry in the chipset's IO-APIC is masked (as, e.g. the RT
 829           kernel does during interrupt handling). On chipsets where this
 830           boot IRQ generation cannot be disabled, this workaround keeps
 831           the original IRQ line masked so that only the equivalent "boot
 832           IRQ" is delivered to the CPUs. The workaround also tells the
 833           kernel to set up the IRQ handler on the boot IRQ line. In this
 834           way only one interrupt is delivered to the kernel. Otherwise
 835           the spurious second interrupt may cause the kernel to bring
 836           down (vital) interrupt lines.
 837
 838           Only affects "broken" chipsets. Interrupt sharing may be
 839           increased on these systems.
 840
 841 config X86_MCE
 842         bool "Machine Check / overheating reporting"
 843         ---help---
 844           Machine Check support allows the processor to notify the
 845           kernel if it detects a problem (e.g. overheating, data corruption).
 846           The action the kernel takes depends on the severity of the problem,
 847           ranging from warning messages to halting the machine.
 848
 849 config X86_MCE_INTEL
 850         def_bool y
 851         prompt "Intel MCE features"
 852         depends on X86_MCE && X86_LOCAL_APIC
 853         ---help---
 854            Additional support for intel specific MCE features such as
 855            the thermal monitor.
 856
 857 config X86_MCE_AMD
 858         def_bool y
 859         prompt "AMD MCE features"
 860         depends on X86_MCE && X86_LOCAL_APIC
 861         ---help---
 862            Additional support for AMD specific MCE features such as
 863            the DRAM Error Threshold.
 864
 865 config X86_ANCIENT_MCE
 866         bool "Support for old Pentium 5 / WinChip machine checks"
 867         depends on X86_32 && X86_MCE
 868         ---help---
 869           Include support for machine check handling on old Pentium 5 or WinChip
 870           systems. These typically need to be enabled explicitely on the command
 871           line.
 872
 873 config X86_MCE_THRESHOLD
 874         depends on X86_MCE_AMD || X86_MCE_INTEL
 875         def_bool y
 876
 877 config X86_MCE_INJECT
 878         depends on X86_MCE
 879         tristate "Machine check injector support"
 880         ---help---
 881           Provide support for injecting machine checks for testing purposes.
 882           If you don't know what a machine check is and you don't do kernel
 883           QA it is safe to say n.
 884
 885 config X86_THERMAL_VECTOR
 886         def_bool y
 887         depends on X86_MCE_INTEL
 888
 889 config VM86
 890         bool "Enable VM86 support" if EMBEDDED
 891         default y
 892         depends on X86_32
 893         ---help---
 894           This option is required by programs like DOSEMU to run 16-bit legacy
 895           code on X86 processors. It also may be needed by software like
 896           XFree86 to initialize some video cards via BIOS. Disabling this
 897           option saves about 6k.
 898
 899 config TOSHIBA
 900         tristate "Toshiba Laptop support"
 901         depends on X86_32
 902         ---help---
 903           This adds a driver to safely access the System Management Mode of
 904           the CPU on Toshiba portables with a genuine Toshiba BIOS. It does
 905           not work on models with a Phoenix BIOS. The System Management Mode
 906           is used to set the BIOS and power saving options on Toshiba portables.
 907
 908           For information on utilities to make use of this driver see the
 909           Toshiba Linux utilities web site at:
 910           <http://www.buzzard.org.uk/toshiba/>.
 911
 912           Say Y if you intend to run this kernel on a Toshiba portable.
 913           Say N otherwise.
 914
 915 config I8K
 916         tristate "Dell laptop support"
 917         ---help---
 918           This adds a driver to safely access the System Management Mode
 919           of the CPU on the Dell Inspiron 8000. The System Management Mode
 920           is used to read cpu temperature and cooling fan status and to
 921           control the fans on the I8K portables.
 922
 923           This driver has been tested only on the Inspiron 8000 but it may
 924           also work with other Dell laptops. You can force loading on other
 925           models by passing the parameter `force=1' to the module. Use at
 926           your own risk.
 927
 928           For information on utilities to make use of this driver see the
 929           I8K Linux utilities web site at:
 930           <http://people.debian.org/~dz/i8k/>
 931
 932           Say Y if you intend to run this kernel on a Dell Inspiron 8000.
 933           Say N otherwise.
 934
 935 config X86_REBOOTFIXUPS
 936         bool "Enable X86 board specific fixups for reboot"
 937         depends on X86_32
 938         ---help---
 939           This enables chipset and/or board specific fixups to be done
 940           in order to get reboot to work correctly. This is only needed on
 941           some combinations of hardware and BIOS. The symptom, for which
 942           this config is intended, is when reboot ends with a stalled/hung
 943           system.
 944
 945           Currently, the only fixup is for the Geode machines using
 946           CS5530A and CS5536 chipsets and the RDC R-321x SoC.
 947
 948           Say Y if you want to enable the fixup. Currently, it's safe to
 949           enable this option even if you don't need it.
 950           Say N otherwise.
 951
 952 config MICROCODE
 953         tristate "/dev/cpu/microcode - microcode support"
 954         select FW_LOADER
 955         ---help---
 956           If you say Y here, you will be able to update the microcode on
 957           certain Intel and AMD processors. The Intel support is for the
 958           IA32 family, e.g. Pentium Pro, Pentium II, Pentium III,
 959           Pentium 4, Xeon etc. The AMD support is for family 0x10 and
 960           0x11 processors, e.g. Opteron, Phenom and Turion 64 Ultra.
 961           You will obviously need the actual microcode binary data itself
 962           which is not shipped with the Linux kernel.
 963
 964           This option selects the general module only, you need to select
 965           at least one vendor specific module as well.
 966
 967           To compile this driver as a module, choose M here: the
 968           module will be called microcode.
 969
 970 config MICROCODE_INTEL
 971         bool "Intel microcode patch loading support"
 972         depends on MICROCODE
 973         default MICROCODE
 974         select FW_LOADER
 975         ---help---
 976           This options enables microcode patch loading support for Intel
 977           processors.
 978
 979           For latest news and information on obtaining all the required
 980           Intel ingredients for this driver, check:
 981           <http://www.urbanmyth.org/microcode/>.
 982
 983 config MICROCODE_AMD
 984         bool "AMD microcode patch loading support"
 985         depends on MICROCODE
 986         select FW_LOADER
 987         ---help---
 988           If you select this option, microcode patch loading support for AMD
 989           processors will be enabled.
 990
 991 config MICROCODE_OLD_INTERFACE
 992         def_bool y
 993         depends on MICROCODE
 994
 995 config X86_MSR
 996         tristate "/dev/cpu/*/msr - Model-specific register support"
 997         ---help---
 998           This device gives privileged processes access to the x86
 999           Model-Specific Registers (MSRs).  It is a character device with
1000           major 202 and minors 0 to 31 for /dev/cpu/0/msr to /dev/cpu/31/msr.
1001           MSR accesses are directed to a specific CPU on multi-processor
1002           systems.
1003
1004 config X86_CPUID
1005         tristate "/dev/cpu/*/cpuid - CPU information support"
1006         ---help---
1007           This device gives processes access to the x86 CPUID instruction to
1008           be executed on a specific processor.  It is a character device
1009           with major 203 and minors 0 to 31 for /dev/cpu/0/cpuid to
1010           /dev/cpu/31/cpuid.
1011
1012 choice
1013         prompt "High Memory Support"
1014         default HIGHMEM64G if X86_NUMAQ
1015         default HIGHMEM4G
1016         depends on X86_32
1017
1018 config NOHIGHMEM
1019         bool "off"
1020         depends on !X86_NUMAQ
1021         ---help---
1022           Linux can use up to 64 Gigabytes of physical memory on x86 systems.
1023           However, the address space of 32-bit x86 processors is only 4
1024           Gigabytes large. That means that, if you have a large amount of
1025           physical memory, not all of it can be "permanently mapped" by the
1026           kernel. The physical memory that's not permanently mapped is called
1027           "high memory".
1028
1029           If you are compiling a kernel which will never run on a machine with
1030           more than 1 Gigabyte total physical RAM, answer "off" here (default
1031           choice and suitable for most users). This will result in a "3GB/1GB"
1032           split: 3GB are mapped so that each process sees a 3GB virtual memory
1033           space and the remaining part of the 4GB virtual memory space is used
1034           by the kernel to permanently map as much physical memory as
1035           possible.
1036
1037           If the machine has between 1 and 4 Gigabytes physical RAM, then
1038           answer "4GB" here.
1039
1040           If more than 4 Gigabytes is used then answer "64GB" here. This
1041           selection turns Intel PAE (Physical Address Extension) mode on.
1042           PAE implements 3-level paging on IA32 processors. PAE is fully
1043           supported by Linux, PAE mode is implemented on all recent Intel
1044           processors (Pentium Pro and better). NOTE: If you say "64GB" here,
1045           then the kernel will not boot on CPUs that don't support PAE!
1046
1047           The actual amount of total physical memory will either be
1048           auto detected or can be forced by using a kernel command line option
1049           such as "mem=256M". (Try "man bootparam" or see the documentation of
1050           your boot loader (lilo or loadlin) about how to pass options to the
1051           kernel at boot time.)
1052
1053           If unsure, say "off".
1054
1055 config HIGHMEM4G
1056         bool "4GB"
1057         depends on !X86_NUMAQ
1058         ---help---
1059           Select this if you have a 32-bit processor and between 1 and 4
1060           gigabytes of physical RAM.
1061
1062 config HIGHMEM64G
1063         bool "64GB"
1064         depends on !M386 && !M486
1065         select X86_PAE
1066         ---help---
1067           Select this if you have a 32-bit processor and more than 4
1068           gigabytes of physical RAM.
1069
1070 endchoice
1071
1072 choice
1073         depends on EXPERIMENTAL
1074         prompt "Memory split" if EMBEDDED
1075         default VMSPLIT_3G
1076         depends on X86_32
1077         ---help---
1078           Select the desired split between kernel and user memory.
1079
1080           If the address range available to the kernel is less than the
1081           physical memory installed, the remaining memory will be available
1082           as "high memory". Accessing high memory is a little more costly
1083           than low memory, as it needs to be mapped into the kernel first.
1084           Note that increasing the kernel address space limits the range
1085           available to user programs, making the address space there
1086           tighter.  Selecting anything other than the default 3G/1G split
1087           will also likely make your kernel incompatible with binary-only
1088           kernel modules.
1089
1090           If you are not absolutely sure what you are doing, leave this
1091           option alone!
1092
1093         config VMSPLIT_3G
1094                 bool "3G/1G user/kernel split"
1095         config VMSPLIT_3G_OPT
1096                 depends on !X86_PAE
1097                 bool "3G/1G user/kernel split (for full 1G low memory)"
1098         config VMSPLIT_2G
1099                 bool "2G/2G user/kernel split"
1100         config VMSPLIT_2G_OPT
1101                 depends on !X86_PAE
1102                 bool "2G/2G user/kernel split (for full 2G low memory)"
1103         config VMSPLIT_1G
1104                 bool "1G/3G user/kernel split"
1105 endchoice
1106
1107 config PAGE_OFFSET
1108         hex
1109         default 0xB0000000 if VMSPLIT_3G_OPT
1110         default 0x80000000 if VMSPLIT_2G
1111         default 0x78000000 if VMSPLIT_2G_OPT
1112         default 0x40000000 if VMSPLIT_1G
1113         default 0xC0000000
1114         depends on X86_32
1115
1116 config HIGHMEM
1117         def_bool y
1118         depends on X86_32 && (HIGHMEM64G || HIGHMEM4G)
1119
1120 config X86_PAE
1121         bool "PAE (Physical Address Extension) Support"
1122         depends on X86_32 && !HIGHMEM4G
1123         ---help---
1124           PAE is required for NX support, and furthermore enables
1125           larger swapspace support for non-overcommit purposes. It
1126           has the cost of more pagetable lookup overhead, and also
1127           consumes more pagetable space per process.
1128
1129 config ARCH_PHYS_ADDR_T_64BIT
1130         def_bool X86_64 || X86_PAE
1131
1132 config DIRECT_GBPAGES
1133         bool "Enable 1GB pages for kernel pagetables" if EMBEDDED
1134         default y
1135         depends on X86_64
1136         ---help---
1137           Allow the kernel linear mapping to use 1GB pages on CPUs that
1138           support it. This can improve the kernel's performance a tiny bit by
1139           reducing TLB pressure. If in doubt, say "Y".
1140
1141 # Common NUMA Features
1142 config NUMA
1143         bool "Numa Memory Allocation and Scheduler Support"
1144         depends on SMP
1145         depends on X86_64 || (X86_32 && HIGHMEM64G && (X86_NUMAQ || X86_BIGSMP || X86_SUMMIT && ACPI) && EXPERIMENTAL)
1146         default y if (X86_NUMAQ || X86_SUMMIT || X86_BIGSMP)
1147         ---help---
1148           Enable NUMA (Non Uniform Memory Access) support.
1149
1150           The kernel will try to allocate memory used by a CPU on the
1151           local memory controller of the CPU and add some more
1152           NUMA awareness to the kernel.
1153
1154           For 64-bit this is recommended if the system is Intel Core i7
1155           (or later), AMD Opteron, or EM64T NUMA.
1156
1157           For 32-bit this is only needed on (rare) 32-bit-only platforms
1158           that support NUMA topologies, such as NUMAQ / Summit, or if you
1159           boot a 32-bit kernel on a 64-bit NUMA platform.
1160
1161           Otherwise, you should say N.
1162
1163 comment "NUMA (Summit) requires SMP, 64GB highmem support, ACPI"
1164         depends on X86_32 && X86_SUMMIT && (!HIGHMEM64G || !ACPI)
1165
1166 config K8_NUMA
1167         def_bool y
1168         prompt "Old style AMD Opteron NUMA detection"
1169         depends on X86_64 && NUMA && PCI
1170         ---help---
1171           Enable K8 NUMA node topology detection.  You should say Y here if
1172           you have a multi processor AMD K8 system. This uses an old
1173           method to read the NUMA configuration directly from the builtin
1174           Northbridge of Opteron. It is recommended to use X86_64_ACPI_NUMA
1175           instead, which also takes priority if both are compiled in.
1176
1177 config X86_64_ACPI_NUMA
1178         def_bool y
1179         prompt "ACPI NUMA detection"
1180         depends on X86_64 && NUMA && ACPI && PCI
1181         select ACPI_NUMA
1182         ---help---
1183           Enable ACPI SRAT based node topology detection.
1184
1185 # Some NUMA nodes have memory ranges that span
1186 # other nodes.  Even though a pfn is valid and
1187 # between a node's start and end pfns, it may not
1188 # reside on that node.  See memmap_init_zone()
1189 # for details.
1190 config NODES_SPAN_OTHER_NODES
1191         def_bool y
1192         depends on X86_64_ACPI_NUMA
1193
1194 config NUMA_EMU
1195         bool "NUMA emulation"
1196         depends on X86_64 && NUMA
1197         ---help---
1198           Enable NUMA emulation. A flat machine will be split
1199           into virtual nodes when booted with "numa=fake=N", where N is the
1200           number of nodes. This is only useful for debugging.
1201
1202 config NODES_SHIFT
1203         int "Maximum NUMA Nodes (as a power of 2)" if !MAXSMP
1204         range 1 10
1205         default "10" if MAXSMP
1206         default "6" if X86_64
1207         default "4" if X86_NUMAQ
1208         default "3"
1209         depends on NEED_MULTIPLE_NODES
1210         ---help---
1211           Specify the maximum number of NUMA Nodes available on the target
1212           system.  Increases memory reserved to accommodate various tables.
1213
1214 config HAVE_ARCH_BOOTMEM
1215         def_bool y
1216         depends on X86_32 && NUMA
1217
1218 config ARCH_HAVE_MEMORY_PRESENT
1219         def_bool y
1220         depends on X86_32 && DISCONTIGMEM
1221
1222 config NEED_NODE_MEMMAP_SIZE
1223         def_bool y
1224         depends on X86_32 && (DISCONTIGMEM || SPARSEMEM)
1225
1226 config HAVE_ARCH_ALLOC_REMAP
1227         def_bool y
1228         depends on X86_32 && NUMA
1229
1230 config ARCH_FLATMEM_ENABLE
1231         def_bool y
1232         depends on X86_32 && ARCH_SELECT_MEMORY_MODEL && !NUMA
1233
1234 config ARCH_DISCONTIGMEM_ENABLE
1235         def_bool y
1236         depends on NUMA && X86_32
1237
1238 config ARCH_DISCONTIGMEM_DEFAULT
1239         def_bool y
1240         depends on NUMA && X86_32
1241
1242 config ARCH_PROC_KCORE_TEXT
1243         def_bool y
1244         depends on X86_64 && PROC_KCORE
1245
1246 config ARCH_SPARSEMEM_DEFAULT
1247         def_bool y
1248         depends on X86_64
1249
1250 config ARCH_SPARSEMEM_ENABLE
1251         def_bool y
1252         depends on X86_64 || NUMA || (EXPERIMENTAL && X86_32) || X86_32_NON_STANDARD
1253         select SPARSEMEM_STATIC if X86_32
1254         select SPARSEMEM_VMEMMAP_ENABLE if X86_64
1255
1256 config ARCH_SELECT_MEMORY_MODEL
1257         def_bool y
1258         depends on ARCH_SPARSEMEM_ENABLE
1259
1260 config ARCH_MEMORY_PROBE
1261         def_bool X86_64
1262         depends on MEMORY_HOTPLUG
1263
1264 config ILLEGAL_POINTER_VALUE
1265        hex
1266        default 0 if X86_32
1267        default 0xdead000000000000 if X86_64
1268
1269 source "mm/Kconfig"
1270
1271 config HIGHPTE
1272         bool "Allocate 3rd-level pagetables from highmem"
1273         depends on HIGHMEM
1274         ---help---
1275           The VM uses one page table entry for each page of physical memory.
1276           For systems with a lot of RAM, this can be wasteful of precious
1277           low memory.  Setting this option will put user-space page table
1278           entries in high memory.
1279
1280 config X86_CHECK_BIOS_CORRUPTION
1281         bool "Check for low memory corruption"
1282         ---help---
1283           Periodically check for memory corruption in low memory, which
1284           is suspected to be caused by BIOS.  Even when enabled in the
1285           configuration, it is disabled at runtime.  Enable it by
1286           setting "memory_corruption_check=1" on the kernel command
1287           line.  By default it scans the low 64k of memory every 60
1288           seconds; see the memory_corruption_check_size and
1289           memory_corruption_check_period parameters in
1290           Documentation/kernel-parameters.txt to adjust this.
1291
1292           When enabled with the default parameters, this option has
1293           almost no overhead, as it reserves a relatively small amount
1294           of memory and scans it infrequently.  It both detects corruption
1295           and prevents it from affecting the running system.
1296
1297           It is, however, intended as a diagnostic tool; if repeatable
1298           BIOS-originated corruption always affects the same memory,
1299           you can use memmap= to prevent the kernel from using that
1300           memory.
1301
1302 config X86_BOOTPARAM_MEMORY_CORRUPTION_CHECK
1303         bool "Set the default setting of memory_corruption_check"
1304         depends on X86_CHECK_BIOS_CORRUPTION
1305         default y
1306         ---help---
1307           Set whether the default state of memory_corruption_check is
1308           on or off.
1309
1310 config X86_RESERVE_LOW_64K
1311         bool "Reserve low 64K of RAM on AMI/Phoenix BIOSen"
1312         default y
1313         ---help---
1314           Reserve the first 64K of physical RAM on BIOSes that are known
1315           to potentially corrupt that memory range. A numbers of BIOSes are
1316           known to utilize this area during suspend/resume, so it must not
1317           be used by the kernel.
1318
1319           Set this to N if you are absolutely sure that you trust the BIOS
1320           to get all its memory reservations and usages right.
1321
1322           If you have doubts about the BIOS (e.g. suspend/resume does not
1323           work or there's kernel crashes after certain hardware hotplug
1324           events) and it's not AMI or Phoenix, then you might want to enable
1325           X86_CHECK_BIOS_CORRUPTION=y to allow the kernel to check typical
1326           corruption patterns.
1327
1328           Say Y if unsure.
1329
1330 config MATH_EMULATION
1331         bool
1332         prompt "Math emulation" if X86_32
1333         ---help---
1334           Linux can emulate a math coprocessor (used for floating point
1335           operations) if you don't have one. 486DX and Pentium processors have
1336           a math coprocessor built in, 486SX and 386 do not, unless you added
1337           a 487DX or 387, respectively. (The messages during boot time can
1338           give you some hints here ["man dmesg"].) Everyone needs either a
1339           coprocessor or this emulation.
1340
1341           If you don't have a math coprocessor, you need to say Y here; if you
1342           say Y here even though you have a coprocessor, the coprocessor will
1343           be used nevertheless. (This behavior can be changed with the kernel
1344           command line option "no387", which comes handy if your coprocessor
1345           is broken. Try "man bootparam" or see the documentation of your boot
1346           loader (lilo or loadlin) about how to pass options to the kernel at
1347           boot time.) This means that it is a good idea to say Y here if you
1348           intend to use this kernel on different machines.
1349
1350           More information about the internals of the Linux math coprocessor
1351           emulation can be found in <file:arch/x86/math-emu/README>.
1352
1353           If you are not sure, say Y; apart from resulting in a 66 KB bigger
1354           kernel, it won't hurt.
1355
1356 config MTRR
1357         def_bool y
1358         prompt "MTRR (Memory Type Range Register) support" if EMBEDDED
1359         ---help---
1360           On Intel P6 family processors (Pentium Pro, Pentium II and later)
1361           the Memory Type Range Registers (MTRRs) may be used to control
1362           processor access to memory ranges. This is most useful if you have
1363           a video (VGA) card on a PCI or AGP bus. Enabling write-combining
1364           allows bus write transfers to be combined into a larger transfer
1365           before bursting over the PCI/AGP bus. This can increase performance
1366           of image write operations 2.5 times or more. Saying Y here creates a
1367           /proc/mtrr file which may be used to manipulate your processor's
1368           MTRRs. Typically the X server should use this.
1369
1370           This code has a reasonably generic interface so that similar
1371           control registers on other processors can be easily supported
1372           as well:
1373
1374           The Cyrix 6x86, 6x86MX and M II processors have Address Range
1375           Registers (ARRs) which provide a similar functionality to MTRRs. For
1376           these, the ARRs are used to emulate the MTRRs.
1377           The AMD K6-2 (stepping 8 and above) and K6-3 processors have two
1378           MTRRs. The Centaur C6 (WinChip) has 8 MCRs, allowing
1379           write-combining. All of these processors are supported by this code
1380           and it makes sense to say Y here if you have one of them.
1381
1382           Saying Y here also fixes a problem with buggy SMP BIOSes which only
1383           set the MTRRs for the boot CPU and not for the secondary CPUs. This
1384           can lead to all sorts of problems, so it's good to say Y here.
1385
1386           You can safely say Y even if your machine doesn't have MTRRs, you'll
1387           just add about 9 KB to your kernel.
1388
1389           See <file:Documentation/x86/mtrr.txt> for more information.
1390
1391 config MTRR_SANITIZER
1392         def_bool y
1393         prompt "MTRR cleanup support"
1394         depends on MTRR
1395         ---help---
1396           Convert MTRR layout from continuous to discrete, so X drivers can
1397           add writeback entries.
1398
1399           Can be disabled with disable_mtrr_cleanup on the kernel command line.
1400           The largest mtrr entry size for a continuous block can be set with
1401           mtrr_chunk_size.
1402
1403           If unsure, say Y.
1404
1405 config MTRR_SANITIZER_ENABLE_DEFAULT
1406         int "MTRR cleanup enable value (0-1)"
1407         range 0 1
1408         default "0"
1409         depends on MTRR_SANITIZER
1410         ---help---
1411           Enable mtrr cleanup default value
1412
1413 config MTRR_SANITIZER_SPARE_REG_NR_DEFAULT
1414         int "MTRR cleanup spare reg num (0-7)"
1415         range 0 7
1416         default "1"
1417         depends on MTRR_SANITIZER
1418         ---help---
1419           mtrr cleanup spare entries default, it can be changed via
1420           mtrr_spare_reg_nr=N on the kernel command line.
1421
1422 config X86_PAT
1423         def_bool y
1424         prompt "x86 PAT support" if EMBEDDED
1425         depends on MTRR
1426         ---help---
1427           Use PAT attributes to setup page level cache control.
1428
1429           PATs are the modern equivalents of MTRRs and are much more
1430           flexible than MTRRs.
1431
1432           Say N here if you see bootup problems (boot crash, boot hang,
1433           spontaneous reboots) or a non-working video driver.
1434
1435           If unsure, say Y.
1436
1437 config ARCH_USES_PG_UNCACHED
1438         def_bool y
1439         depends on X86_PAT
1440
1441 config EFI
1442         bool "EFI runtime service support"
1443         depends on ACPI
1444         ---help---
1445           This enables the kernel to use EFI runtime services that are
1446           available (such as the EFI variable services).
1447
1448           This option is only useful on systems that have EFI firmware.
1449           In addition, you should use the latest ELILO loader available
1450           at <http://elilo.sourceforge.net> in order to take advantage
1451           of EFI runtime services. However, even with this option, the
1452           resultant kernel should continue to boot on existing non-EFI
1453           platforms.
1454
1455 config SECCOMP
1456         def_bool y
1457         prompt "Enable seccomp to safely compute untrusted bytecode"
1458         ---help---
1459           This kernel feature is useful for number crunching applications
1460           that may need to compute untrusted bytecode during their
1461           execution. By using pipes or other transports made available to
1462           the process as file descriptors supporting the read/write
1463           syscalls, it's possible to isolate those applications in
1464           their own address space using seccomp. Once seccomp is
1465           enabled via prctl(PR_SET_SECCOMP), it cannot be disabled
1466           and the task is only allowed to execute a few safe syscalls
1467           defined by each seccomp mode.
1468
1469           If unsure, say Y. Only embedded should say N here.
1470
1471 config CC_STACKPROTECTOR
1472         bool "Enable -fstack-protector buffer overflow detection (EXPERIMENTAL)"
1473         ---help---
1474           This option turns on the -fstack-protector GCC feature. This
1475           feature puts, at the beginning of functions, a canary value on
1476           the stack just before the return address, and validates
1477           the value just before actually returning.  Stack based buffer
1478           overflows (that need to overwrite this return address) now also
1479           overwrite the canary, which gets detected and the attack is then
1480           neutralized via a kernel panic.
1481
1482           This feature requires gcc version 4.2 or above, or a distribution
1483           gcc with the feature backported. Older versions are automatically
1484           detected and for those versions, this configuration option is
1485           ignored. (and a warning is printed during bootup)
1486
1487 source kernel/Kconfig.hz
1488
1489 config KEXEC
1490         bool "kexec system call"
1491         ---help---
1492           kexec is a system call that implements the ability to shutdown your
1493           current kernel, and to start another kernel.  It is like a reboot
1494           but it is independent of the system firmware.   And like a reboot
1495           you can start any kernel with it, not just Linux.
1496
1497           The name comes from the similarity to the exec system call.
1498
1499           It is an ongoing process to be certain the hardware in a machine
1500           is properly shutdown, so do not be surprised if this code does not
1501           initially work for you.  It may help to enable device hotplugging
1502           support.  As of this writing the exact hardware interface is
1503           strongly in flux, so no good recommendation can be made.
1504
1505 config CRASH_DUMP
1506         bool "kernel crash dumps"
1507         depends on X86_64 || (X86_32 && HIGHMEM)
1508         ---help---
1509           Generate crash dump after being started by kexec.
1510           This should be normally only set in special crash dump kernels
1511           which are loaded in the main kernel with kexec-tools into
1512           a specially reserved region and then later executed after
1513           a crash by kdump/kexec. The crash dump kernel must be compiled
1514           to a memory address not used by the main kernel or BIOS using
1515           PHYSICAL_START, or it must be built as a relocatable image
1516           (CONFIG_RELOCATABLE=y).
1517           For more details see Documentation/kdump/kdump.txt
1518
1519 config KEXEC_JUMP
1520         bool "kexec jump (EXPERIMENTAL)"
1521         depends on EXPERIMENTAL
1522         depends on KEXEC && HIBERNATION
1523         ---help---
1524           Jump between original kernel and kexeced kernel and invoke
1525           code in physical address mode via KEXEC
1526
1527 config PHYSICAL_START
1528         hex "Physical address where the kernel is loaded" if (EMBEDDED || CRASH_DUMP)
1529         default "0x1000000"
1530         ---help---
1531           This gives the physical address where the kernel is loaded.
1532
1533           If kernel is a not relocatable (CONFIG_RELOCATABLE=n) then
1534           bzImage will decompress itself to above physical address and
1535           run from there. Otherwise, bzImage will run from the address where
1536           it has been loaded by the boot loader and will ignore above physical
1537           address.
1538
1539           In normal kdump cases one does not have to set/change this option
1540           as now bzImage can be compiled as a completely relocatable image
1541           (CONFIG_RELOCATABLE=y) and be used to load and run from a different
1542           address. This option is mainly useful for the folks who don't want
1543           to use a bzImage for capturing the crash dump and want to use a
1544           vmlinux instead. vmlinux is not relocatable hence a kernel needs
1545           to be specifically compiled to run from a specific memory area
1546           (normally a reserved region) and this option comes handy.
1547
1548           So if you are using bzImage for capturing the crash dump,
1549           leave the value here unchanged to 0x1000000 and set
1550           CONFIG_RELOCATABLE=y.  Otherwise if you plan to use vmlinux
1551           for capturing the crash dump change this value to start of
1552           the reserved region.  In other words, it can be set based on
1553           the "X" value as specified in the "crashkernel=YM@XM"
1554           command line boot parameter passed to the panic-ed
1555           kernel. Please take a look at Documentation/kdump/kdump.txt
1556           for more details about crash dumps.
1557
1558           Usage of bzImage for capturing the crash dump is recommended as
1559           one does not have to build two kernels. Same kernel can be used
1560           as production kernel and capture kernel. Above option should have
1561           gone away after relocatable bzImage support is introduced. But it
1562           is present because there are users out there who continue to use
1563           vmlinux for dump capture. This option should go away down the
1564           line.
1565
1566           Don't change this unless you know what you are doing.
1567
1568 config RELOCATABLE
1569         bool "Build a relocatable kernel"
1570         default y
1571         ---help---
1572           This builds a kernel image that retains relocation information
1573           so it can be loaded someplace besides the default 1MB.
1574           The relocations tend to make the kernel binary about 10% larger,
1575           but are discarded at runtime.
1576
1577           One use is for the kexec on panic case where the recovery kernel
1578           must live at a different physical address than the primary
1579           kernel.
1580
1581           Note: If CONFIG_RELOCATABLE=y, then the kernel runs from the address
1582           it has been loaded at and the compile time physical address
1583           (CONFIG_PHYSICAL_START) is ignored.
1584
1585 # Relocation on x86-32 needs some additional build support
1586 config X86_NEED_RELOCS
1587         def_bool y
1588         depends on X86_32 && RELOCATABLE
1589
1590 config PHYSICAL_ALIGN
1591         hex "Alignment value to which kernel should be aligned" if X86_32
1592         default "0x1000000"
1593         range 0x2000 0x1000000
1594         ---help---
1595           This value puts the alignment restrictions on physical address
1596           where kernel is loaded and run from. Kernel is compiled for an
1597           address which meets above alignment restriction.
1598
1599           If bootloader loads the kernel at a non-aligned address and
1600           CONFIG_RELOCATABLE is set, kernel will move itself to nearest
1601           address aligned to above value and run from there.
1602
1603           If bootloader loads the kernel at a non-aligned address and
1604           CONFIG_RELOCATABLE is not set, kernel will ignore the run time
1605           load address and decompress itself to the address it has been
1606           compiled for and run from there. The address for which kernel is
1607           compiled already meets above alignment restrictions. Hence the
1608           end result is that kernel runs from a physical address meeting
1609           above alignment restrictions.
1610
1611           Don't change this unless you know what you are doing.
1612
1613 config HOTPLUG_CPU
1614         bool "Support for hot-pluggable CPUs"
1615         depends on SMP && HOTPLUG
1616         ---help---
1617           Say Y here to allow turning CPUs off and on. CPUs can be
1618           controlled through /sys/devices/system/cpu.
1619           ( Note: power management support will enable this option
1620             automatically on SMP systems. )
1621           Say N if you want to disable CPU hotplug.
1622
1623 config COMPAT_VDSO
1624         def_bool y
1625         prompt "Compat VDSO support"
1626         depends on X86_32 || IA32_EMULATION
1627         ---help---
1628           Map the 32-bit VDSO to the predictable old-style address too.
1629
1630           Say N here if you are running a sufficiently recent glibc
1631           version (2.3.3 or later), to remove the high-mapped
1632           VDSO mapping and to exclusively use the randomized VDSO.
1633
1634           If unsure, say Y.
1635
1636 config CMDLINE_BOOL
1637         bool "Built-in kernel command line"
1638         ---help---
1639           Allow for specifying boot arguments to the kernel at
1640           build time.  On some systems (e.g. embedded ones), it is
1641           necessary or convenient to provide some or all of the
1642           kernel boot arguments with the kernel itself (that is,
1643           to not rely on the boot loader to provide them.)
1644
1645           To compile command line arguments into the kernel,
1646           set this option to 'Y', then fill in the
1647           the boot arguments in CONFIG_CMDLINE.
1648
1649           Systems with fully functional boot loaders (i.e. non-embedded)
1650           should leave this option set to 'N'.
1651
1652 config CMDLINE
1653         string "Built-in kernel command string"
1654         depends on CMDLINE_BOOL
1655         default ""
1656         ---help---
1657           Enter arguments here that should be compiled into the kernel
1658           image and used at boot time.  If the boot loader provides a
1659           command line at boot time, it is appended to this string to
1660           form the full kernel command line, when the system boots.
1661
1662           However, you can use the CONFIG_CMDLINE_OVERRIDE option to
1663           change this behavior.
1664
1665           In most cases, the command line (whether built-in or provided
1666           by the boot loader) should specify the device for the root
1667           file system.
1668
1669 config CMDLINE_OVERRIDE
1670         bool "Built-in command line overrides boot loader arguments"
1671         depends on CMDLINE_BOOL
1672         ---help---
1673           Set this option to 'Y' to have the kernel ignore the boot loader
1674           command line, and use ONLY the built-in command line.
1675
1676           This is used to work around broken boot loaders.  This should
1677           be set to 'N' under normal conditions.
1678
1679 endmenu
1680
1681 config ARCH_ENABLE_MEMORY_HOTPLUG
1682         def_bool y
1683         depends on X86_64 || (X86_32 && HIGHMEM)
1684
1685 config ARCH_ENABLE_MEMORY_HOTREMOVE
1686         def_bool y
1687         depends on MEMORY_HOTPLUG
1688
1689 config HAVE_ARCH_EARLY_PFN_TO_NID
1690         def_bool X86_64
1691         depends on NUMA
1692
1693 config USE_PERCPU_NUMA_NODE_ID
1694         def_bool X86_64
1695         depends on NUMA
1696
1697 menu "Power management and ACPI options"
1698
1699 config ARCH_HIBERNATION_HEADER
1700         def_bool y
1701         depends on X86_64 && HIBERNATION
1702
1703 source "kernel/power/Kconfig"
1704
1705 source "drivers/acpi/Kconfig"
1706
1707 source "drivers/sfi/Kconfig"
1708
1709 config X86_APM_BOOT
1710         def_bool y
1711         depends on APM || APM_MODULE
1712
1713 menuconfig APM
1714         tristate "APM (Advanced Power Management) BIOS support"
1715         depends on X86_32 && PM_SLEEP
1716         ---help---
1717           APM is a BIOS specification for saving power using several different
1718           techniques. This is mostly useful for battery powered laptops with
1719           APM compliant BIOSes. If you say Y here, the system time will be
1720           reset after a RESUME operation, the /proc/apm device will provide
1721           battery status information, and user-space programs will receive
1722           notification of APM "events" (e.g. battery status change).
1723
1724           If you select "Y" here, you can disable actual use of the APM
1725           BIOS by passing the "apm=off" option to the kernel at boot time.
1726
1727           Note that the APM support is almost completely disabled for
1728           machines with more than one CPU.
1729
1730           In order to use APM, you will need supporting software. For location
1731           and more information, read <file:Documentation/power/pm.txt> and the
1732           Battery Powered Linux mini-HOWTO, available from
1733           <http://www.tldp.org/docs.html#howto>.
1734
1735           This driver does not spin down disk drives (see the hdparm(8)
1736           manpage ("man 8 hdparm") for that), and it doesn't turn off
1737           VESA-compliant "green" monitors.
1738
1739           This driver does not support the TI 4000M TravelMate and the ACER
1740           486/DX4/75 because they don't have compliant BIOSes. Many "green"
1741           desktop machines also don't have compliant BIOSes, and this driver
1742           may cause those machines to panic during the boot phase.
1743
1744           Generally, if you don't have a battery in your machine, there isn't
1745           much point in using this driver and you should say N. If you get
1746           random kernel OOPSes or reboots that don't seem to be related to
1747           anything, try disabling/enabling this option (or disabling/enabling
1748           APM in your BIOS).
1749
1750           Some other things you should try when experiencing seemingly random,
1751           "weird" problems:
1752
1753           1) make sure that you have enough swap space and that it is
1754           enabled.
1755           2) pass the "no-hlt" option to the kernel
1756           3) switch on floating point emulation in the kernel and pass
1757           the "no387" option to the kernel
1758           4) pass the "floppy=nodma" option to the kernel
1759           5) pass the "mem=4M" option to the kernel (thereby disabling
1760           all but the first 4 MB of RAM)
1761           6) make sure that the CPU is not over clocked.
1762           7) read the sig11 FAQ at <http://www.bitwizard.nl/sig11/>
1763           8) disable the cache from your BIOS settings
1764           9) install a fan for the video card or exchange video RAM
1765           10) install a better fan for the CPU
1766           11) exchange RAM chips
1767           12) exchange the motherboard.
1768
1769           To compile this driver as a module, choose M here: the
1770           module will be called apm.
1771
1772 if APM
1773
1774 config APM_IGNORE_USER_SUSPEND
1775         bool "Ignore USER SUSPEND"
1776         ---help---
1777           This option will ignore USER SUSPEND requests. On machines with a
1778           compliant APM BIOS, you want to say N. However, on the NEC Versa M
1779           series notebooks, it is necessary to say Y because of a BIOS bug.
1780
1781 config APM_DO_ENABLE
1782         bool "Enable PM at boot time"
1783         ---help---
1784           Enable APM features at boot time. From page 36 of the APM BIOS
1785           specification: "When disabled, the APM BIOS does not automatically
1786           power manage devices, enter the Standby State, enter the Suspend
1787           State, or take power saving steps in response to CPU Idle calls."
1788           This driver will make CPU Idle calls when Linux is idle (unless this
1789           feature is turned off -- see "Do CPU IDLE calls", below). This
1790           should always save battery power, but more complicated APM features
1791           will be dependent on your BIOS implementation. You may need to turn
1792           this option off if your computer hangs at boot time when using APM
1793           support, or if it beeps continuously instead of suspending. Turn
1794           this off if you have a NEC UltraLite Versa 33/C or a Toshiba
1795           T400CDT. This is off by default since most machines do fine without
1796           this feature.
1797
1798 config APM_CPU_IDLE
1799         bool "Make CPU Idle calls when idle"
1800         ---help---
1801           Enable calls to APM CPU Idle/CPU Busy inside the kernel's idle loop.
1802           On some machines, this can activate improved power savings, such as
1803           a slowed CPU clock rate, when the machine is idle. These idle calls
1804           are made after the idle loop has run for some length of time (e.g.,
1805           333 mS). On some machines, this will cause a hang at boot time or
1806           whenever the CPU becomes idle. (On machines with more than one CPU,
1807           this option does nothing.)
1808
1809 config APM_DISPLAY_BLANK
1810         bool "Enable console blanking using APM"
1811         ---help---
1812           Enable console blanking using the APM. Some laptops can use this to
1813           turn off the LCD backlight when the screen blanker of the Linux
1814           virtual console blanks the screen. Note that this is only used by
1815           the virtual console screen blanker, and won't turn off the backlight
1816           when using the X Window system. This also doesn't have anything to
1817           do with your VESA-compliant power-saving monitor. Further, this
1818           option doesn't work for all laptops -- it might not turn off your
1819           backlight at all, or it might print a lot of errors to the console,
1820           especially if you are using gpm.
1821
1822 config APM_ALLOW_INTS
1823         bool "Allow interrupts during APM BIOS calls"
1824         ---help---
1825           Normally we disable external interrupts while we are making calls to
1826           the APM BIOS as a measure to lessen the effects of a badly behaving
1827           BIOS implementation.  The BIOS should reenable interrupts if it
1828           needs to.  Unfortunately, some BIOSes do not -- especially those in
1829           many of the newer IBM Thinkpads.  If you experience hangs when you
1830           suspend, try setting this to Y.  Otherwise, say N.
1831
1832 endif # APM
1833
1834 source "arch/x86/kernel/cpu/cpufreq/Kconfig"
1835
1836 source "drivers/cpuidle/Kconfig"
1837
1838 source "drivers/idle/Kconfig"
1839
1840 endmenu
1841
1842
1843 menu "Bus options (PCI etc.)"
1844
1845 config PCI
1846         bool "PCI support"
1847         default y
1848         select ARCH_SUPPORTS_MSI if (X86_LOCAL_APIC && X86_IO_APIC)
1849         ---help---
1850           Find out whether you have a PCI motherboard. PCI is the name of a
1851           bus system, i.e. the way the CPU talks to the other stuff inside
1852           your box. Other bus systems are ISA, EISA, MicroChannel (MCA) or
1853           VESA. If you have PCI, say Y, otherwise N.
1854
1855 choice
1856         prompt "PCI access mode"
1857         depends on X86_32 && PCI
1858         default PCI_GOANY
1859         ---help---
1860           On PCI systems, the BIOS can be used to detect the PCI devices and
1861           determine their configuration. However, some old PCI motherboards
1862           have BIOS bugs and may crash if this is done. Also, some embedded
1863           PCI-based systems don't have any BIOS at all. Linux can also try to
1864           detect the PCI hardware directly without using the BIOS.
1865
1866           With this option, you can specify how Linux should detect the
1867           PCI devices. If you choose "BIOS", the BIOS will be used,
1868           if you choose "Direct", the BIOS won't be used, and if you
1869           choose "MMConfig", then PCI Express MMCONFIG will be used.
1870           If you choose "Any", the kernel will try MMCONFIG, then the
1871           direct access method and falls back to the BIOS if that doesn't
1872           work. If unsure, go with the default, which is "Any".
1873
1874 config PCI_GOBIOS
1875         bool "BIOS"
1876
1877 config PCI_GOMMCONFIG
1878         bool "MMConfig"
1879
1880 config PCI_GODIRECT
1881         bool "Direct"
1882
1883 config PCI_GOOLPC
1884         bool "OLPC"
1885         depends on OLPC
1886
1887 config PCI_GOANY
1888         bool "Any"
1889
1890 endchoice
1891
1892 config PCI_BIOS
1893         def_bool y
1894         depends on X86_32 && PCI && (PCI_GOBIOS || PCI_GOANY)
1895
1896 # x86-64 doesn't support PCI BIOS access from long mode so always go direct.
1897 config PCI_DIRECT
1898         def_bool y
1899         depends on PCI && (X86_64 || (PCI_GODIRECT || PCI_GOANY || PCI_GOOLPC))
1900
1901 config PCI_MMCONFIG
1902         def_bool y
1903         depends on X86_32 && PCI && (ACPI || SFI) && (PCI_GOMMCONFIG || PCI_GOANY)
1904
1905 config PCI_OLPC
1906         def_bool y
1907         depends on PCI && OLPC && (PCI_GOOLPC || PCI_GOANY)
1908
1909 config PCI_DOMAINS
1910         def_bool y
1911         depends on PCI
1912
1913 config PCI_MMCONFIG
1914         bool "Support mmconfig PCI config space access"
1915         depends on X86_64 && PCI && ACPI
1916
1917 config PCI_CNB20LE_QUIRK
1918         bool "Read CNB20LE Host Bridge Windows"
1919         depends on PCI
1920         help
1921           Read the PCI windows out of the CNB20LE host bridge. This allows
1922           PCI hotplug to work on systems with the CNB20LE chipset which do
1923           not have ACPI.
1924
1925 config DMAR
1926         bool "Support for DMA Remapping Devices (EXPERIMENTAL)"
1927         depends on PCI_MSI && ACPI && EXPERIMENTAL
1928         help
1929           DMA remapping (DMAR) devices support enables independent address
1930           translations for Direct Memory Access (DMA) from devices.
1931           These DMA remapping devices are reported via ACPI tables
1932           and include PCI device scope covered by these DMA
1933           remapping devices.
1934
1935 config DMAR_DEFAULT_ON
1936         def_bool y
1937         prompt "Enable DMA Remapping Devices by default"
1938         depends on DMAR
1939         help
1940           Selecting this option will enable a DMAR device at boot time if
1941           one is found. If this option is not selected, DMAR support can
1942           be enabled by passing intel_iommu=on to the kernel. It is
1943           recommended you say N here while the DMAR code remains
1944           experimental.
1945
1946 config DMAR_BROKEN_GFX_WA
1947         bool "Workaround broken graphics drivers (going away soon)"
1948         depends on DMAR && BROKEN
1949         ---help---
1950           Current Graphics drivers tend to use physical address
1951           for DMA and avoid using DMA APIs. Setting this config
1952           option permits the IOMMU driver to set a unity map for
1953           all the OS-visible memory. Hence the driver can continue
1954           to use physical addresses for DMA, at least until this
1955           option is removed in the 2.6.32 kernel.
1956
1957 config DMAR_FLOPPY_WA
1958         def_bool y
1959         depends on DMAR
1960         ---help---
1961           Floppy disk drivers are known to bypass DMA API calls
1962           thereby failing to work when IOMMU is enabled. This
1963           workaround will setup a 1:1 mapping for the first
1964           16MiB to make floppy (an ISA device) work.
1965
1966 config INTR_REMAP
1967         bool "Support for Interrupt Remapping (EXPERIMENTAL)"
1968         depends on X86_64 && X86_IO_APIC && PCI_MSI && ACPI && EXPERIMENTAL
1969         ---help---
1970           Supports Interrupt remapping for IO-APIC and MSI devices.
1971           To use x2apic mode in the CPU's which support x2APIC enhancements or
1972           to support platforms with CPU's having > 8 bit APIC ID, say Y.
1973
1974 source "drivers/pci/pcie/Kconfig"
1975
1976 source "drivers/pci/Kconfig"
1977
1978 # x86_64 have no ISA slots, but do have ISA-style DMA.
1979 config ISA_DMA_API
1980         def_bool y
1981
1982 if X86_32
1983
1984 config ISA
1985         bool "ISA support"
1986         ---help---
1987           Find out whether you have ISA slots on your motherboard.  ISA is the
1988           name of a bus system, i.e. the way the CPU talks to the other stuff
1989           inside your box.  Other bus systems are PCI, EISA, MicroChannel
1990           (MCA) or VESA.  ISA is an older system, now being displaced by PCI;
1991           newer boards don't support it.  If you have ISA, say Y, otherwise N.
1992
1993 config EISA
1994         bool "EISA support"
1995         depends on ISA
1996         ---help---
1997           The Extended Industry Standard Architecture (EISA) bus was
1998           developed as an open alternative to the IBM MicroChannel bus.
1999
2000           The EISA bus provided some of the features of the IBM MicroChannel
2001           bus while maintaining backward compatibility with cards made for
2002           the older ISA bus.  The EISA bus saw limited use between 1988 and
2003           1995 when it was made obsolete by the PCI bus.
2004
2005           Say Y here if you are building a kernel for an EISA-based machine.
2006
2007           Otherwise, say N.
2008
2009 source "drivers/eisa/Kconfig"
2010
2011 config MCA
2012         bool "MCA support"
2013         ---help---
2014           MicroChannel Architecture is found in some IBM PS/2 machines and
2015           laptops.  It is a bus system similar to PCI or ISA. See
2016           <file:Documentation/mca.txt> (and especially the web page given
2017           there) before attempting to build an MCA bus kernel.
2018
2019 source "drivers/mca/Kconfig"
2020
2021 config SCx200
2022         tristate "NatSemi SCx200 support"
2023         ---help---
2024           This provides basic support for National Semiconductor's
2025           (now AMD's) Geode processors.  The driver probes for the
2026           PCI-IDs of several on-chip devices, so its a good dependency
2027           for other scx200_* drivers.
2028
2029           If compiled as a module, the driver is named scx200.
2030
2031 config SCx200HR_TIMER
2032         tristate "NatSemi SCx200 27MHz High-Resolution Timer Support"
2033         depends on SCx200
2034         default y
2035         ---help---
2036           This driver provides a clocksource built upon the on-chip
2037           27MHz high-resolution timer.  Its also a workaround for
2038           NSC Geode SC-1100's buggy TSC, which loses time when the
2039           processor goes idle (as is done by the scheduler).  The
2040           other workaround is idle=poll boot option.
2041
2042 config OLPC
2043         bool "One Laptop Per Child support"
2044         select GPIOLIB
2045         ---help---
2046           Add support for detecting the unique features of the OLPC
2047           XO hardware.
2048
2049 config OLPC_OPENFIRMWARE
2050         bool "Support for OLPC's Open Firmware"
2051         depends on !X86_64 && !X86_PAE
2052         default y if OLPC
2053         help
2054           This option adds support for the implementation of Open Firmware
2055           that is used on the OLPC XO-1 Children's Machine.
2056           If unsure, say N here.
2057
2058 endif # X86_32
2059
2060 config K8_NB
2061         def_bool y
2062         depends on CPU_SUP_AMD && PCI
2063
2064 source "drivers/pcmcia/Kconfig"
2065
2066 source "drivers/pci/hotplug/Kconfig"
2067
2068 endmenu
2069
2070
2071 menu "Executable file formats / Emulations"
2072
2073 source "fs/Kconfig.binfmt"
2074
2075 config IA32_EMULATION
2076         bool "IA32 Emulation"
2077         depends on X86_64
2078         select COMPAT_BINFMT_ELF
2079         ---help---
2080           Include code to run 32-bit programs under a 64-bit kernel. You should
2081           likely turn this on, unless you're 100% sure that you don't have any
2082           32-bit programs left.
2083
2084 config IA32_AOUT
2085         tristate "IA32 a.out support"
2086         depends on IA32_EMULATION
2087         ---help---
2088           Support old a.out binaries in the 32bit emulation.
2089
2090 config COMPAT
2091         def_bool y
2092         depends on IA32_EMULATION
2093
2094 config COMPAT_FOR_U64_ALIGNMENT
2095         def_bool COMPAT
2096         depends on X86_64
2097
2098 config SYSVIPC_COMPAT
2099         def_bool y
2100         depends on COMPAT && SYSVIPC
2101
2102 endmenu
2103
2104
2105 config HAVE_ATOMIC_IOMAP
2106         def_bool y
2107         depends on X86_32
2108
2109 source "net/Kconfig"
2110
2111 source "drivers/Kconfig"
2112
2113 source "drivers/firmware/Kconfig"
2114
2115 source "fs/Kconfig"
2116
2117 source "arch/x86/Kconfig.debug"
2118
2119 source "security/Kconfig"
2120
2121 source "crypto/Kconfig"
2122
2123 source "arch/x86/kvm/Kconfig"
2124
2125 source "lib/Kconfig"